Item: The Influence of Weather on Glide-Snow Avalanches
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Title: The Influence of Weather on Glide-Snow Avalanches
Proceedings: International Snow Science Workshop Grenoble – Chamonix Mont-Blanc - October 07-11, 2013
Authors:
- Lisa Dreier [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Christoph Mitterer [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
- Sebastian Feick [ Institute of Geography, University of Erlangen-Nürnberg, Germany ]
- Stephan Harvey [ WSL Institute for Snow and Avalanche Research SLF, Davos, Switzerland ]
Date: 2013-10-07
Abstract: During the winter 2011-2012 the Swiss Alps experienced high glide-snow activity. The danger of glide-snow avalanches combined with large snow depths posed a challenge to the local authorities. Glide-snow avalanches are difficult to predict and hard to control. Weather, snowpack, soil and terrain are known to influence snow gliding. So far, however, no clear relationship between these variables and glide-snow activity could be established. Many research results report that a wet basal layer is paramount for the formation of glide-snow avalanches. Based on observations, the assumption is made that different processes favor the production of this basal layer and thus the triggering of snow gliding in winter and in spring. In winter the snowpack is usually cold and dry, in spring it’s warm and wet. Thus, there are different processes causing water at the snow-soil boundary. In order to shed some light into these two different periods, glide-snow activity was monitored at a well-known glidesnow avalanche site, the Dorfberg above Davos, Switzerland during the winter seasons 2008-2009 and 2011-2012 using time-lapse photography. Glide-snow avalanche activity was compared to weather parameters of a nearby weather station. We used univariate and multivariate statistical methods to explore the data. Results verify different processes in winter and spring. Most important weather parameters in winter are maximal air temperature, the 5-day sum of new snow and incoming shortwave radiation. In spring, the parameters snow surface temperature, minimal air temperature, difference in air temperature to the day before and relative humidity seem most important. The difference in important parameters for winter and spring periods indicate different sources of the thin water layer at the snow-soil interface and therefore different underlying processes that lead to snow gliding.
Language of Article: English
Presenters: Unknown
Keywords: snow gliding, weather influence, glide-snow avalanche, multivariate statistic
Page Number(s): 247-252
Subjects: glide avalanches snow gliding weather conditions
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Digital Abstract Not Available
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